P1546

Schematic:

CIRCUIT DESCRIPTION
Output Driver Modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and Transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the device which the PCM is commanding ON. Unlike the Quad Driver Modules (QDMs) used in prior model years, ODMs have the capability of diagnosing each output circuit individually. DTC P1546 set indicates an improper voltage level has been detected on the output circuit which controls the A/C compressor control relay.

CONDITIONS FOR RUNNING THE DTC
The ignition is ON.

CONDITIONS FOR SETTING THE DTC
^ An improper voltage level has been detected on the output circuit which controls the A/C compressor control relay.
^ The above conditions are present for at least 30 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using a scan tool.

DIAGNOSTIC AIDS
Inspect for the following:

IMPORTANT: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

^ Poor terminal connection.
Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Diagrams.
^ Damaged harness.
Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display may indicate the location of the fault. Refer to Wiring Repairs in Diagrams.
^ Inspect the PCM and the engine grounds for clean and secure connections.

If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set.

TEST DESCRIPTION

Diagnostic Chart:

The numbers below refer to the step numbers on the diagnostic table.
1. The powertrain OBD System Check prompts you to complete some basic checks and store the freeze frame and failure records data on the scan tool.
2. Listen for an audible click when the relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the coil feed side of the relay.
4. Verifies that the PCM is providing ground to the relay.
5. Tests if ground is constantly being applied to the relay.
12. The PCM utilizes Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.